Remote sensing
GEOG 40323
March 20, 2018
Raster data: a brief review
- Used to represent continuous phenomena
- Each grid cell or pixel has a specific value

Types of raster data

Raster data resolution
- Data with a smaller cell dimension have a higher resolution

Remote sensing and photogrammetry
- Remote sensing: collection of aerial and satellite images for use within a GIS
- Photogrammetry: the science of measuring geometry from images
Electromagnetic energy
- Properties: wavelength, frequency, and amplitude

Resolution in remote sensing
- Relevant types:
- Spatial resolution
- Temporal resolution
- Spectral resolution
- Radiometric resolution
Data collection: satellites

Data collection: satellites

Types of satellites
- Landsat
- GeoEye/Digital Globe
Data collection: airplanes

Remotely sensed data models
- Raster data (imagery)
- Point cloud data (LIDAR)
Imagery in a GIS

- Data types: GeoTIFF, GeoJPEG, ECW, GRID, IMG, SID
Mosaicing
- Process of combining multiple rasters into a single dataset

Imagery operations
- Georeferencing
- Orthorectification
- Spectral enhancement
Normalized Difference Vegetation Index

Band manipulation

Image classification
- Types: supervised and unsupervised classification

Change detection

Urban applications of remote sensing